The present invention relates to a hybrid compressor having two drive means, that is employed in an air-conditioning system mounted in a hybrid vehicle which is driven by two drive means, i.e., an internal combustion engine and an electric motor.
The hybrid compressor disclosed in Japanese Unexamined Utility Model Publication No.H-87678 is provided with two drive sources, i.e., an engine and a battery-driven motor unit to drive the rotating shaft at the compression unit so that the rotating shaft at the compression unit is driven by either of the two drive sources that are selectively connected to the rotating shaft. In the hybrid compressor, the motor shaft of the motor is linked to the rotating shaft at the compression unit, and an electromagnetic clutch is provided between a pulley to which the motive power of the engine is communicated and a pulley to which the motive power of the rotating shaft is communicated, and either the rotating shaft or the motor shaft, so that the rotation of one of the pulleys is selectively communicated to the rotating shaft. The electromagnetic clutch is electrically connected in such a manner that by turning on the electromagnetic clutch, the motive power from the engine causes the rotor at the motor unit to rotate to charge the batteries and that, by turning off the electromagnetic clutch, the motor unit is caused to rotate on power supplied by the batteries.
However, the hybrid compressor described above having the electromagnetic clutch and the motor provided on one side of the rotating shaft at the compression unit necessitates a rotor constituting the motor and the armature of the electromagnetic clutch to be mounted as an integrated part of the rotating shaft with the stator of the electric motor jointly mounted at the supporting/retaining portion of the electromagnetic clutch, resulting in a highly complicated structure. In addition, as illustrated in FIG. 2 of the publication quoted above, when providing the motor on the outside of the electromagnetic clutch, the distance between the compression unit and the rotor of the motor increases, and this poses a problem in that the torsional torque occurring at the rotating shaft and the motor shaft causes damage to the retaining area over which the rotating shaft and the motor shaft are secured to each other. Furthermore, it is not desirable for a compressor mounted within the engine room to assume a structure having the motor unit projecting out beyond the electromagnetic clutch.
Accordingly, an object of the present invention is to provide a hybrid compressor that achieves simplification in its structure and a higher degree of ease for driving the compression unit.
In the hybrid compressor according to the present invention comprising a compression unit having a rotating shaft and a compression space, the volumetric capacity of which is varied through the rotation of the rotating shaft, a pulley mounted at the rotating shaft of the compression unit, to which the rotation of an internal combustion engine is communicated, an electromagnetic clutch that selectively connects the pulley to the rotating shaft to communicate the rotation of the internal combustion engine to the rotating shaft and an electric motor unit constituted of a rotor secured to the rotating shaft and a stator facing opposite the rotor. The rotating shaft passes through the compression unit, the electromagnetic clutch is provided at the rotating shaft projecting out on one side of the compression unit and the electric motor unit is provided at the rotating shaft projecting out on the other side of the compression unit in this hybrid compressor.
Thus, since the electromagnetic clutch is provided at the rotating shaft projecting out on one side of the compression unit and the electric motor unit is provided at the rotating shaft projecting out on the other side of the compression unit, an electromagnetic clutch in the prior art can be directly utilized. In addition, since the electric motor unit is provided at the rotating shaft projecting out on the other side of the compression unit, the electric motor and the electromagnetic clutch are provided at the same rotating shaft and the compression unit and the electric motor unit can be set adjacent to each other to achieve the object described above.
In addition, it is desirable that the hybrid compressor assume a structure of a rotary compressor in which the compression unit is constituted of a rotor secured to the rotating shaft and a compression space, the volumetric capacity of which is varied through the rotation of the rotor. The hybrid compressor should preferably be provided with a capacity-varying mechanism that varies the discharge quantity by varying the position at which the intake port opens during an intake process in which the compression space expands in response to the rotation of the rotor.
Alternatively, the hybrid compressor may assume a structure of a piston-type compressor in which the compression unit is provided with a plurality of cylinders formed along the direction of the axis of the rotating shaft and pistons caused to engage in reciprocal movement inside the cylinders by the rotation of the rotating shaft. In this case, the hybrid compressor should preferably be provided with a capacity-varying mechanism that varies the discharge volume by varying the angle of a rotating inclined plate that causes the piston to move reciprocally within the cylinder as the rotating shaft rotates to limit the distance over which the piston travels.
Since the rotary compressor and the piston-type compressor both assume a structure that accommodates the rotating shaft to pass through the compression unit and the presence of the capacity-varying mechanism enables control for reducing the startup torque, problems that would otherwise occur at the startup of the electric motor can be prevented.